Inside caliper



Nov. 26, 1940. E. MULLER INSIDE CALIF-ER Filed Feb. 25, 1958 l Si ATTORNEY Patented Nov. 26, 1940 UNITED STATES INSIDE CALIPER Ernest Muller, Oakland, Calif.

Application February 25, 1938, Serial No. 192,530

8 Claims.

The invention relates to measuring tools and more particularly to an inside caliper of the type generally known in the art as a telescope gauge. An object of the present invention is to pro- 5y vide an inside caliper of the character described which is so constructed and arranged as to permit the use of the instrument in narrower and shallower slots and openings and the like for a given size of the instrument and to enable the positionl ing of the measuring parts of the instrument closer to shoulders and slots and opening side walls than has been heretofore possible in the present type of caliper.

Another object of the invention is to provide i a caliper of the character above which is made substantially easier and cheaper to manufacture by the use of a one piece combination set and locking pin andthe use of simple pressed fits and other features of construction.

Another object of the invention is to provide alcaliper of the character described which may be simply and quickly disassembled and the several movable parts thereof completely removed for cleaning, inspection or replacement.

The invention possesses other objects and'features ofA advantage, some of which, with the foregoing, will be set forth in the following description of the `preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specication. It is to be understood, however, that variations in the showing made by the said drawing and description may be adopted within the scope of the invention as set forth in the claims.

Referring to said drawing: 4

Figure l is a side elevation of an inside caliper constructed in accordance with the present invention.

Figure 2 is a longitudinal sectional view of the caliper. i

Figure 3 is a plan view of thepcaliper as the same appears when fully compacted and placed ina cylindrical opening.

Figure 4 is a cross sectional view of the handle taken substantially on the plane of line 4-4 of Figure 2. Y

Figure 5 is a cross sectional view of the handle taken substantially on the plane of line 5-5 of Figure 2.

Figure 6 is a plan View of a collar forming part of the tool.

Figure '7 is an end elevation of the collar illustrated in Figure 6. Y v

Figure 8is a plan view of a blank of material 55 from/which the 'collar islpressed. 3

Figure 9 is a plan view of the inside section *l of the measuring cross head of the caliper.

The inside caliper of the present invention, and asv illustrated in the accompanying drawing, as above indicated, is of the so-called telescope gauge type having a handle II and a measuring cross-head including inner and outer telescopic sections I2 and I3 of tubular form and arranged with the inner section I2 extendible from an open end I4 of the outer section. The outer ends I6 and I'I of the members I2 and I3 are closed tubes to press them towards a relative extended position of the inner tube. In common with other calipers of this general type, the present caliper is assembled by connecting the handle II to the outer cross head member I3 and providing within the handle an adjustable means for engaging the inner section` I2 for holding the latter in adjusted position. In addition, it is necessary in this type of measuring tool to provide means for preventing a disengagement of the inner and outer sections under the expansion action of the spring, and in previous devices this latter means has frequently been arranged independent of the adjustment locking means. In

other of the prior devices the means for locking the sections in adjusted position and the means for preventing separation of the inner and outer tubular members has been somewhat combined by the use of a two piece locking pin, wherein one section of the locking pin was constantly held in engagement with a clos-ed ended slot in the inner section to prevent a separation of the telescopic sections and a second pin section which was'adapted to bear against the first pin section for forcing the latter against the inner telescopic section for holding the same against movement in adjusted position.

The present inside caliper, as aforementioned, is generally related to similar devices heretofore used and it will, therefore, be understood that the present invention lies not in a new type of measuring tool but rather to various improved features on the type of tool above described.

Inv accordance with the present invention I have substantially simplified the means for holdist ` ing the telescopic sections in adjusted position and preventing separation of the sections when released by the use of a single one piece locking pin 22 which is utilized for both of these functions. Also, I have arranged for an improved form of connection between the handle and the outer telescopic section which substantially simplifies and cheapens the cost of manufacture and improves the usefulness of the tool by enabling a closer positioning of the tool to various parts to be measured, thereby enabling the calipering 0f shallower and narrower slots and openings i and the like for a given size tool, than has been` possible heretofore. The means of connection between the handle and outer telescopic sections is here effectedby means of a collar 23 formed frornat stockfsee v Figure 8, and stamped and formed in Y'ai die so as to provide a cylindrical portion 24 which is preferably pressed-onto the outer periphery of the member I3 andi arranged thereon Withone end 26-of the cylindrical portion substantially flush with the open end I4 ofthe tubular member I3. The collar is additionally provided With a'laterally extending tubular portion "21, which islikewise preferably formed in a die together with the portion 24 and from ythe saine'stock, land is preferably pressed into a bore 28 in the handle `I I vopening to one end 29 of the handle. Thehandle end 29 is preferably curved toconform to the cylindrical shape of the collar so that the lower end -29 of the handle will snugly engage aroundA the curved periphery of the collar. One of theimportant features of this construction Vliesv infth'e fact that the nat stock, out of Which the collar is made, mayV be stamped or otherwise impressed witha name or. other identifying data, whereas the applying of such data to acylindrical .surface requires a rolling process.. Also, the 40. Y

forming ofY the collarfout of .a flat strip which may be stamped and pressed up in a' die, materially reduces the cost olf construction. and simplifies the manufacture of this part ,of the caliper. In addition, the forming of the collar out of iat stock enables the use of relatively thin lmaterial in the collar so as to produce a minimum obstruction around the outer tubular member, as may interfere with the insertion of the measuring `cross-'head vinto relatively narrow or shallovv'slots and openings and the like. In this connection applicant further provides for a beveling of the end -26 ofthe collar, s o as to remove the laterally extending material of the collar at the'end of vthe tubular member, whereby the cross-head may ist be'inserted in an opening having'a diameter'substantially yequal to the'length of the outer tubular membensee Fgure'. This is of considerable importance enabling a measuring of openings of minimum size where the inner section is substantially completely retracted into the uter section.

v '-Ihe means 'for holding the sections in adjusted position against thefexpansion action 'of the Aspring YI8 and the means'for preventing complete `Separatio`n of the inner tubular section fro-m the outer tubular section under the urge of the spring, is effected as above noted, by the use'fia single one piece locking piny 22 Which is carried inthe handle bore 28 and extends'I for substantially the full length'of the handle and extends 'through/an opening 3| provided in the outer telescopic "sectionadjacent the end- 2B thereof forengagement in a closed ended long'i# tudinalfslot 32 in the periphery of the inner member'. In order to obtain a maximum relative movement of the inner and outer sections of the measuring cross-head, the slot 32 is extended for substantially the full length of the inner section and is provided with closed ends 33 and 34 adjacent the ends of the inner section, and the pin 22 is positioned as near as possible to the end 26 of the outer section so as to enable a maximum extension of the inner section. In order to obtain this latter positioning of the pin and forother reasons as" ftvill be j. hereinafter mentioned, the bore 28 in the handle is arranged at the end 29 of the handle eccentrically to the axis of the handle and as near to the end 23 .Z'Iof-'the collar is formed substantially at the end 23 lofV the collar. In this manner the lower end of the locking p-in is positioned as'close as po-ssible'to the open end of the outer section, so

as to permit ya maximum extension of the inner section.: 1 n Y 'L ,The sections are secured in adjusted position by pressing the locking pin longitudinally through the "handle to bear against" the inner'telescopic 'member andas herefshowrnthe means. for .so urging they pin Yhere consists of a cap 36 threaded Ainto the outerfend of the bore 26and provided withia tubular' portion. 3l somewhat largerjthan the diameter' ofthe pin'for. loosely Viitting over the outer end off the ,pin'and adapted to seat against the pin in itsinvvardly threaded position in the handle. Preferably, the", outer portion ,of the cap and the outer-portion of the handle'are knurled in order to facilitate relative turningI of the cap and handle for`locking andy releasing the telescopic sections.

The means for holding 'the telescopic sections against separation' upon unscrewing the cap-*36 `to-release the pressure on the pin`22, hee'con- 'sists of laterally extending linter-engaging'por- ,tionson the pin and handle and which are normally aligned so as tof prevent retraction of the pin out ofthe slot- 32intheinner telescopic section. The inter-engaging'fmeans aforesaid here ,consistsfof an annular VgrooveS provided on the pinY adjacent the outer endarranged oppositely .tofanannular shoulderf39 in the bore 28 inthe handle. .The internal diameter of the shoulder 3,9 ispreferably slightly larger -than the diameter Aofthe pin, so as to permit passage of the pin through theV opening in theshoulderand .the groove in the pin is normally held in positionfto engagethe shoulder by the holding of the pin in a longitudinally inclined position Athrough the bore so as to enter one side of the shoulder into the lspace* of the groove. This is effected in part by the arrangement of the pin opening inthe ,outer telescopic section and the eccentric lposition of the pin opening at the end 29 of the handle and ythe action-of the cap 36 to substantially centralize the outer end of thepin inthe bora. so that the axis of the pin will be inclined generally to the axis of the bore. Tol'hold the pin in this inclined position, the pin opening inv the outer telescopic vsection ispreferably of smaller size than thev bore andonlya little larger than the pinitselfj -On therother handfthe bore isjof substantially larger 'diameter than the pinso that upon removal of thecap- '36, the pin may be shifted laterally in the bore to align the pin withthe-opening in the shoulder 39 to therebyenable withdrawal of the pin from the bore,- v'U-pon such- Withdra-Wal -of the pin, the-innertelescopic section may be AremovedfromV theoutergsection and the several moving parts of the tool disassembled for cleaning, inspection, repair .or replacement.

handle having a longitudinally. extending bore therethrough, a measuring cross-head formed of .telescopically arranged inner and outer slidably engaged members with the vinner of said members being extendible from an open: end of'said outer member, said outer` memberLbei'ng secured to said handle adjacent the open end thereof, and means carried by said handle .for holding said members 'in adjusted position comprising, aA locking pin carried in saidhandl'ejb'ore andengageable with said inner' member, and vmeans nfor pressing'said pin against said inner member, said bore having an 'axis inclined `to the axis of said handle so as to positionith'e' head end Vof said bore adjacent the open end of said outer member.

2. An inside caliper comprising, an elongated handle having a bore therethrough, a measuring cross-head formed of a pair of telescopically mounted tubular members arranged with an inner member extendible from an open end of an outer member, said outer member being secured to said handle adjacent said open end, spring means carried by said members for urging the outward extension of said inner member, said inner member being provided with'a closed ended longitudinally extending groove in the outer periphery thereof, and a locking pin carried by said handle in said bore for engaging in said groove for holding said members in adjusted position and for preventing withdrawal of said inner member from said outer member, said bore opening to the head end of said handle eccentrically to the axis of said handle towards the open end of said outer member so as to aiord a maximum extension of said inner member.

3.' An inside caliper comprising, an elongated handle having a bore therethrough, a measuring cross-head formed of a pair of telescopically mounted tubular members arranged with an inner member extendible from an open end oi an outer member, said outer member being secured to said handle adjacent said `open end, spring means carried by said members for urging the outward extension of said inner member, said inner member being provided with a closed ended longitudinally extending groove in the outer periphery thereof, a one piece locking pin carried in said handle bore and extending substantially the full length of said handle and having one end engaged in said groove, means for pressing said pin into said groove, and laterally ex- .tending interengaging means on said pin and handle operative to retain said pin in said groove.

4. An inside caliper comprising, an elongated handle having a bore therethrough, a measuring cross-head formed of a pair of telescopically mounted tubular members arranged with an inner member extendible from an open end of an outer member, said outer member being secured to said handle adjacent said open end, spring means carried by said members for urging the outward extension of said inner member, said inner member being provided with a closed ended longitudinally extending groove in the outer periphery thereof, a one piece locking pin carried in said handle bore and extending substantially the full length of said handle and having one end engaged in said groove, means for pressing said pin into said groove, and laterally extending interengaging means on said pin and handle operative to retain said pin in said groove, said bore inlsaid handle being sufficiently largerlthan said Vpin to enable disengagement of said last named means and withdrawal of said pin.

5. An inside caliper comprising, an elongated 'handle having abore therethrough, a measuring .s

cross-head formed of a .pair of telescopically mounted tubular members arranged with an inner member exte-ndible from an` open end of an .outer member, said outermember being secured -to said handle vadjacent said open end, spring lmeans'carried by said members for urging the outward extension of said inner member, said .inner member being provided with a closed ended longitudinally extending groove in the' outer .periphery thereof, a one-piece locking pincarried .in said handle'bore and extending substantially vthe full length of said handle and having one end engaged in said groove, means for pressing said pin into said groove, and laterally extending `interlengaging means on said pin and handle opera?- ive to retain said pin in said groove, saidbore having an axis inclined to the axis of said handle so as to normally retain said last named means in position for engagement.

6. An inside caliper comprising, an elongated handle having a bore therethrough, a measuring cross-head formed of a pair of telescopically mounted tubular members arranged with an inner member extendible from an open end of an outer member, said outer member being secured to said handle adjacent said open end, spring means carried bysaid members for urging the outward extension of said inner member, said inner member being provided with a closed ended longitudinally extending groove in the outer periphery thereof, a one piece locking pin carried in said handle bore and extending substantially the full length of said handle and having one end engaged in said groove, laterally extending interengaging means on said pin and handle operative to retain said pin in said groove, said bore having an axis inclined to the axis of said handle, and means at the outer end of said handle for centralizing said pin and for holding said last named means in position for engagement, said last named means being removable from said handle and said bore being larger than said pin whereby on removal of said last named means said pin may be displaced laterally to disengage said interengaging means.

"1. An inside caliper comprising, an elongated handle having a bore therethrough, a measuring cross-head formed of a pair of telescopically mounted tubular members arranged with an inner member extendible from an open end of an outer member, said outer member being secured to said handle adjacent said open end, spring means carried by said members for urging the outward extension of said inner member, said inner member being provided with a closed ended longitudinally extending groove in the outer periphery thereof, a one piece locking pin carried in said handle bore and extending substantially the full length of said handle and having one end engaged in said groove, means for pressing said pin into said groove, laterally extending interengaging means on said pin and handle operative to retain said pin in said groove, said bore having an axis inclined to the axis of said handle, means at the outer end of said handle for centralizing said pin and for holding said last named means in position for engagement, said pin being formed intermediate its length with an annular groove, said bore being of a larger diameter than said pin and having an M annular inwardly! extending', shoulder of slightly u said: pin kfrom said member groove, and means for pressing saidpin. into said member grooveto hold v+ said members: in adjusted position.:A

. 8. An inside.calipercomprising an elongated y10] handle, a measuring cross-head formed of telescopic sections including an inner section ex- 'tendible from :an open endv of an outer section, 4said outer section being secured to one end of y said handle adjacent its'open end; spring means 15. "carried by said sections vfor urging the outward extension of said inner section, said inner section "being provided With a longitudinally extending closed ended slot in its periphery, said handle l being provided with a longitudinal bore register- NingfSWith an opening through said outer section 'adjacent the openY end thereof, said opening in .justed position.' 1

-saidouter member bengfosrnalleidiainterrthan said bore and arranged eccentricallyithereto;;a locking pin carried in said bore and;;extendi11g 'through said opening ltinto engagements. in .said slot, isaid pinfloeing'.` provided with 'an' annular ranged within said borerand; totherebymaintain the axis of` saidzpin-inclin'ed td the axisoff said bore 'and said shoulder engaged in said groove vto prevent Withdrawal of said?v pin from said section slot, said cap beingadapted togpress against the outerend of said pin to, locksaid sections-inad- ERNsT MULLER. 

